There are two basic types of internal combustion piston engines. One of these is the Otto cycle wherein a mixture of fuel and air is drawn into a cylinder, is compressed and is then ignited by a spark plug with the resulting explosion or combustion of the fuel driving the piston to expand the chamber and to do work. The other common cycle is the Diesel cycle wherein air is compressed to a relatively high pressure and fuel is injected into the cylinder after the compression is substantially completed and ignites due to the temperature and pressure of the air into which it is injected.
Many variations of these basic cycles and many methods of improving their efficiency have been proposed. It is desired to improve this efficiency not only for economic reasons but also in order to assure substantially complete combustion and reduce the amount of unburned fuel which is exhausted by the engine as a potential air or water pollutent. Various additives for fuels have been used as have various means for controlling the injections and combustion of fuel. It has been proposed to have the fuel injected into the chamber through a spark gap, for example, in an effort to improve combustion. Various types of spark plugs and fuel injecting mechanisms have been proposed. Recently there has been proposed an engine which has a specially designed cylinder or piston to provide a special precombustion gas chamber with a glow wire disposed in it. This arrangement was proposed primarily for natural gas engines and required substantial modification of the engine.
In spite of the efforts to improve internal combustion engines, it is well known that there remains room for a great deal of improvement. This invention provides an improved apparatus for controlling the amount of fuel injected into the cylinders of an internal combustion engine.